2

I'm working on a job scheduling app for a REST API and I've created a Tasks, Nodes, URL, Adom, BaseOptions, and Jobs tables in Django. The BaseOptions have a foreign key for src_adom and dst_adom and the Jobs have foreign keys for the Task, src_node, dst_node, url and baseOptions. I didn't use a ModelForm but a generic Form instead and just loaded up the initial values and choices for all the fields I need in order to process a job. I did that because I couldn't figure out how to make the form change when the user selects a different node and want to change the select field for the corresponding adoms. I'm using javascript to detect a new node and changing the select field with the appropriate adoms for that node. I get a validation error if I change the initial source and/or destination node and modify the adom selection list. I know it is because my list of choices have changed from what I initially rendered the form with.

Is there a way to change the choices associated with a ChoiceField during the "clean" method? I can't seem to find that in the documents or digging through the Django code on github.

Models:

FMG = 'FMG'
FOS = 'FOS'
NODE_TYPE_CHOICES = (
    (FMG, 'FMG'),
    (FOS, 'FOS'),
)

# Create the types of tasks to run
class TaskType(models.Model):
    name = models.CharField(max_length=200)
    command = models.CharField(max_length=200)
    node_type = models.CharField(max_length=60, choices=NODE_TYPE_CHOICES, default=FMG)

    def __str__(self):
        return self.name

# Create the nodes for tasks to be run on
class Node(models.Model):
    ip = models.GenericIPAddressField(protocol='IPv4')
    name = models.CharField(max_length=200)
    apiname = models.CharField(max_length=200)
    apikey = EncryptedCharField(max_length=200)
    node_type = models.CharField(max_length=60, choices=NODE_TYPE_CHOICES, default=FMG)

    def __str__(self):
        return "{0} ({1})".format(self.name, self.ip)

class FMG_URLManger(models.Manager):

    def get_queryset(self):
        return super(FMG_URLManger, self).get_queryset().filter(node_type='FMG')

class FOS_URLManger(models.Manager):

    def get_queryset(self):
        return super(FOS_URLManger, self).get_queryset().filter(node_type='FOS')

class NodeURL(models.Model):
    name = models.CharField(max_length=200)
    node_type = models.CharField(max_length=60, choices=NODE_TYPE_CHOICES, default=FMG)
    table_id = models.CharField(max_length=100)
    table_url = models.CharField(max_length=200)
    help_text = models.CharField(max_length=400, null=True)
    filename = models.CharField(max_length=200)

    objects = models.Manager()
    fmg_objects = FMG_URLManger()
    fos_objects = FOS_URLManger()

    def __str__(self):
        return self.name

class Adom(models.Model):
    name = models.CharField(max_length=200)
    version = models.CharField(max_length=60)
    fmg = models.ForeignKey(Node, related_name='fmgs', on_delete=models.CASCADE)

    class Meta:
        unique_together = (("name", "version", "fmg"),)

    def __str__(self):
        return self.name

class BaseOption(models.Model):
    src_adom = models.ForeignKey(Adom, related_name="src_adom", on_delete=models.CASCADE)
    dst_adom = models.ForeignKey(Adom, related_name="dst_adom", on_delete=models.CASCADE, null=True)
    name_filter = models.CharField(max_length=100, null=True)
    site_name_filter = models.CharField(max_length=100, null=True)
    policy_id_list_filter = models.CharField(max_length=60, null=True)
    keep_policy_id = models.BooleanField(default=False)
    disable_policy = models.BooleanField(default=False)
    import_only = models.BooleanField(default=False)

    def __str__(self):
        return self.src_adom.name

# Create the actual request for jobs
class Job(models.Model):
    UNKNOWN = 'Unknown'
    PENDING = 'Pending'
    SUCCESS = 'Success'
    FAILURE = 'Failure'
    STATUS_CHOICES = (
        (UNKNOWN, 'Unknown'),
        (PENDING, 'Pending'),
        (SUCCESS, 'Success'),
        (FAILURE, 'Failure'),
    )
    description = models.CharField(max_length=400)
    task = models.ForeignKey(TaskType, related_name='job_task', on_delete=models.CASCADE)
    src_node = models.ForeignKey(Node, related_name='src_node', on_delete=models.CASCADE)
    urls = models.ManyToManyField(NodeURL)
    dst_node = models.ForeignKey(Node, related_name='dst_node', on_delete=models.CASCADE)
    user = models.ForeignKey(User, related_name='jobs', on_delete=models.CASCADE)
    opts = models.OneToOneField(BaseOption, related_name='job', on_delete=models.CASCADE)
    created = models.DateTimeField(auto_now_add=True)
    run_at = models.DateTimeField(editable=True, default=timezone.now)
    start = models.DateTimeField(editable=True, null=True)
    finished = models.DateTimeField(editable=True, null=True)
    status = models.CharField(max_length=12, choices=STATUS_CHOICES, default=UNKNOWN, editable=True)
    status_text = models.TextField(editable=True, null=True)
    file_location = models.CharField(max_length=4086, editable=True, null=True)

    objects = models.Manager()

    def __str__(self):
        return self.description

The ScheduleFormView:

class ScheduleView(LoginRequiredMixin, generic.FormView):

    login_url = '/login/'
    redirect_field_name = 'redirect_to'

    template_name = 'tools/schedule.html'
    form_class = ScheduleJobForm

    def post(self, request, *args, **kwargs):
        form = self.form_class(request.POST)
        print("Got a POST request, checking for valid...")
        if form.is_valid():
            # <process form cleaned data>
            taskID_nodeType = form.cleaned_data['task']
            description = form.cleaned_data['description']
            src_nodeID_name = form.cleaned_data['src_node']
            dst_nodeID_name = form.cleaned_data['dst_node']
            urlsID_tableID = form.cleaned_data['urls']
            src_adomID = form.cleaned_data['src_adom']
            dst_adomID = form.cleaned_data['dst_adom']
            name_filter = form.cleaned_data['name_filter']
            site_name_fiter = form.cleaned_data['site_name_fiter']
            policy_id_list_filter = form.cleaned_data['policy_id_list_filter']
            taskID = taskID_nodeType.split('.')[0]
            src_nodeID = src_nodeID_name.split('.')[0]
            dst_nodeID = dst_nodeID_name.split('.')[0]
            # urlsID_tableID was a list, now it's a single URL
            # urlIDs = []
            # for urlID_tableID in urlsID_tableID:
            #     urlID = urlID_tableID.split('.')[0]
            #     print("Got back id {}".format(urlID))
            #     urlIDs.append(urlID)
            urlID = urlsID_tableID.split('.')[0]
            urls = NodeURL.objects.filter(id=urlID)
            # print("List of URLS = {}".format(urls))
            src_node = Node.objects.get(id=src_nodeID)
            dst_node = Node.objects.get(id=dst_nodeID)
            task = TaskType.objects.get(id=taskID)
            src_adom = Adom.objects.get(id=src_adomID)
            dst_adom = Adom.objects.get(id=dst_adomID)
            job = Job(description=description,
                    task=task,
                    src_node=src_node,
                    dst_node=dst_node,
                    user=request.user)
            opts = BaseOption(src_adom=src_adom,
                            dst_adom=dst_adom,
                            name_filter=name_filter,
                            site_name_filter=site_name_fiter,
                            policy_id_list_filter=policy_id_list_filter)
            opts.save()
            job.opts = opts
            job.save()
            for url in urls:
                url.job_set.add(job)
            return HttpResponseRedirect('job-list.html')
        else:
            print("The form was not valid. Return for more processing.")

        return render(request, self.template_name, {'form': form})

The ScheduleJobForm (with my unfinished code for 'clean'):

class ScheduleJobForm(forms.Form):

    def clean(self):

        print("Don't actually check for on src_adom.")
        cleaned_data = super(ScheduleJobForm, self).clean()
        print(cleaned_data)
        adom = self.cleaned_data.get("src_adom")
        print(adom)
        # if adom < 1:
        #     raise forms.ValidationError("You didn't choose a valid ADOM.")

        print("Don't actually check for on dst_adom.")
        cleaned_data = super(ScheduleJobForm, self).clean()
        adom = self.cleaned_data.get("dst_adom")
        print(adom)
        # if adom < 1:
        #     raise forms.ValidationError("You didn't choose a valid ADOM.")

    initTasks = []
    selectedNodeType = ''
    # Get the first node_type because it will be the default selection of tasks.
    for task in TaskType.objects.all().filter(node_type='FMG').order_by('id'):
        if selectedNodeType == '':
            selectedNodeType = task.node_type
        taskChoice = str(task.id) + '.' + task.node_type, task.name
        initTasks.append(taskChoice)
    # Fill in the initial Nodes for the selected task above.
    initNodes = []
    selectedNodeID = 0
    for node in Node.objects.all().filter(node_type=selectedNodeType).order_by('id'):
        nodeChoice = str(node.id) + '.' + node.name, node.name + ' (' + node.ip + ')'
        if selectedNodeID == 0:
            selectedNodeID = node.id
        initNodes.append(nodeChoice)
    # Also grab the URL's for those node types and fill them in.
    initURLs = []
    for url in NodeURL.objects.all().filter(node_type=selectedNodeType).order_by('table_id'):
        urlChoice = str(url.id) + '.' + url.table_id, url.name
        initURLs.append(urlChoice)
    # Since we've got the first node selected, then all the ADOMs are the same. Get them.
    initAdoms = []
    for adom in Adom.objects.all().filter(fmg_id=selectedNodeID).order_by('id'):
        adomChoice = adom.id, adom.name
        initAdoms.append(adomChoice)
    # Add some hidden fields for the jQuery script to examine.
    selected_node_type = forms.CharField(initial=selectedNodeType, widget=forms.HiddenInput)
    # After this, a jQuery will have to keep the select fields updated if they are changed.
    task = forms.ChoiceField(choices=initTasks)
    description = forms.CharField()
    src_node = forms.ChoiceField(choices=initNodes)
    dst_node = forms.ChoiceField(choices=initNodes)
    urls = forms.ChoiceField(choices=initURLs)
    # These fields will have to be updated by the jQuery to get the available ADOMS for the selected
    # Nodes. We also have to create a custom validator since the choices will change via the JS.
    src_adom = forms.ChoiceField(choices=initAdoms)
    dst_adom = forms.ChoiceField(choices=initAdoms)
    name_filter = forms.CharField()
    site_name_fiter = forms.CharField()
    policy_id_list_filter = forms.CharField()

The schedule.js script that modifies the adoms:

/* 
Of cource, I could use the following but I think the code below is
a bit more readable.
$(function(){
    initPage();
}
); */
const coreapi = window.coreapi
const schema = window.schema

$(document).ready(function(){
        initPage();
    }
);

function initPage() {

    console.log("Adding the change code.")

    // Fill in the initial srcAdom
    getSrcAdom()
    // and the initial dstAdom
    getDstAdom()
    // Hide the wait icon
    $('.loading').hide();

    $('#id_task').change(
        function() {
            var currentNodeType = $('#id_selected_node_type').val();
            var selectedOption = $('#id_task option:selected').val();
            var selectedNodeType = selectedOption.split(".").pop();
            if (currentNodeType != selectedNodeType) {
                // The more I look at the options, I think this will have to be locked
                // into FMG only nodes and create another form for just FOS nodes.
            }
        }
    );

    $('#id_src_node').change(
        function() {
            // Need to change the src adoms
            $('.loading').show();
            getSrcAdom()
            $('.loading').hide();
        }
    );

    $('#id_dst_node').change(
        function() {
            // Need to change the src adoms
            $('.loading').show();
            getDstAdom()
            $('.loading').hide();
        }
    );

}

function getSrcAdom() {
    var selectedOption = $('#id_src_node option:selected').val();
    var selectedNodeName = selectedOption.split(".").pop();

    // Clear the src adom options.
    $('#id_src_adom')
    .find('option')
    .remove();

    // Initialize a client
    var client = new coreapi.Client()

    // Interact with the API endpoint
    var action = ["adom", "list"]
    var params = {
        search: selectedNodeName,
    }
    client.action(schema, action, params).then(function(result) {
        // Return value is in 'result'
        $.each(result, function(index, obj) {
            $('#id_src_adom')
            .append('<option value="' + obj["id"] + '">' + obj["name"] + '</option>');
            console.log(index + " got '" + obj["name"] + "' (id: " + obj["id"] + ")");
        })
    })
}

function getDstAdom() {
    var selectedOption = $('#id_dst_node option:selected').val();
    var selectedNodeName = selectedOption.split(".").pop();

    // Clear the src adom options.
    $('#id_dst_adom')
    .find('option')
    .remove();

    // Initialize a client
    var client = new coreapi.Client()

    // Interact with the API endpoint
    var action = ["adom", "list"]
    var params = {
        search: selectedNodeName,
    }
    client.action(schema, action, params).then(function(result) {
        // Return value is in 'result'
        $.each(result, function(index, obj) {
            $('#id_dst_adom')
            .append('<option value="' + obj["id"] + '">' + obj["name"] + '</option>');
            console.log(index + " got '" + obj["name"] + "' (id: " + obj["id"] + ")");
        })
    })
}

function createNodeSelect(data) {
    // This was to clear all selected nodes and list new node types.
    // It's not going to be used in this form at this time.
    // Need to determine data format from JSON return.
    // Leaving for future code example of how to clear options
    // and replace it with a single option.
    $('#id_src_node')
    .find('option')
    .remove()
    .end()
    .append('<option value="whatever">text</option>')
    .val('whatever');
}

The schedule.html template (with Bootstrap 4 tags):

{% extends "tools/base_site.html" %}

{% block extra_js %}
    {% load static %}
        <script src="{% static 'rest_framework/js/coreapi-0.1.1.js' %}"></script>
        <script src="{% url 'api-docs:schema-js' %}"></script>
        <script src="{% static 'js/schedule.js' %}"></script>
{% endblock %}

{% block content %}
        <div id="content-main">
            <br>
            {% block loading %}
            {% load static %}
            <div id="loading" class="loading">
                <img src="{% static 'images/spinning-wait-icons/wait30.gif' %}" alt="Wait" />
                <!-- <h3>Loading Data from Server</h3> -->
            </div>
            {% endblock %}
            {% load widget_tweaks %}
            {% if form.errors %}
                <div class="alert alert-primary">
                    <button type="button" class="close" data-dismiss="alert">×</button>
                    {% for field in form %} 
                        {% if field.errors %}
                        <li>{{ field.label }}: {{ field.errors|striptags }}</li>
                        {% endif %}
                    {% endfor %}
                </div>
            {% endif %}
            <form method="post">
                {% csrf_token %}

                {% for hidden_field in form.hidden_fields %}
                    {{ hidden_field }}
                {% endfor %}

                {% for field in form.visible_fields %}
                    <div class="form-group">
                    {{ field.label_tag }}
                    {% render_field field class="form-control" %}
                    {% if field.help_text %}
                        <small class="form-text text-muted">{{ field.help_text }}</small>
                    {% endif %}
                    </div>
                {% endfor %}

                <button type="submit" class="btn btn-primary">Schedule</button>
            </form>
        </div>
{% endblock %}

2 Answers2

0

I must confess I didn't go through all the code (it's quite a lot), but at a first glance it looks to me as you should move the initialization of your choices (intTasks, initNodes...) into the __init__ method of your FormClass (ScheduleJobForm). Because you want the code to be run when you instantiate the class, not when you load the module, right? So:

class ScheduleJobForm(forms.Form):
    selected_node_type = forms.CharField(initial=selectedNodeType, widget=forms.HiddenInput)
    task = forms.ChoiceField(choices=initTasks)
    # further fields

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # initialize initNodes and the rest
        self.fields["src_node"]=initNodes
        # and resp.

The form does not care about Javascript, as it is instantiated in the post request after all the Javascript magic on the frontend. So there doesn't have to (and cannot) be any interaction between Javascript and your form.

crystalAhmet
  • 346
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  • That is an excellent suggestion that I will likely implement since it's more like what I'm doing when first rendering the form. However, that's not my problem. I start off with Node_1 selected that has ADOM_1 and ADOM_2 associated with it so they are the only two in the ADOM ChoiceField list. If I change the Node ChoiceField to Node_2, the ADOM ChoiceField will be changed via the javascript to have ADOM_3 and ADOM_4 in it. When I POST that back, I'm told 4 is not a valid choice because it only started with 1 and 2. – mwclark4453 Jul 26 '18 at 15:36
0

I was able to figure out how to dynamically change the choices by using the getter and setter property of ChoiceField (see github repo).

The change I made was in the ScheduleJobForm view. I added these additional lines before calling 'is_valid':

        print("Got a POST request, checking for valid...")
        print("Fix the choices in the ADOMs first.")
        src_nodeID_name = form['src_node'].value()
        dst_nodeID_name = form['dst_node'].value()
        src_nodeID = src_nodeID_name.split('.')[0]
        dst_nodeID = dst_nodeID_name.split('.')[0]
        srcAdoms = []
        for adom in Adom.objects.all().filter(fmg_id=src_nodeID).order_by('id'):
            adomChoice = adom.id, adom.name
            srcAdoms.append(adomChoice)
        dstAdoms = []
        for adom in Adom.objects.all().filter(fmg_id=dst_nodeID).order_by('id'):
            adomChoice = adom.id, adom.name
            dstAdoms.append(adomChoice)
        form.fields['src_adom'].choices = srcAdoms
        form.fields['dst_adom'].choices = dstAdoms

For efficiency, I should probably check changed_data and see if the ADOM's have actually changed or not.